That will not help, I'm quite sure. We have a lot of workflows running happily but some are running into error state with above mentioned error message. Of course this happens to different workflows and most of their instances are running fine.

thank you very much for pointing out possible solutions. Especially the hint with state machines seems quite valueable to me. We have many workflows with lots of instances running hust fine. It is just the occasional one instance here and one instance there which fails. And now that you mention it, it's always the ones with state machines that fail.

We also have really huge workflows and those are already split according to what you mentioned. I.e. one workflow coordinating the others. No single workflow is bigger than 250k.

I'll look after an offline window and then install the latest version. Hopefully that'll make things better.